Hand-held motor-driven shear



March 17, 1953 Q GRAY 2,631,370

HAND-HELD MOTOR-DRIVEN SHEAR Filed April 28, 195} CHAR ES B GRAY BY 0%I? T TORIVEV Patented Mar. 17, 1953 UNITED STATES PATENT OFFICE 5Claims.

This invention relates generally to motordriven sheet-metal cuttingtools and more particularly to improvements in the construction ofhand-held, electrically operated shears of the type shown and describedin my prior United States Letters Patent No. 1,922,846 of August 15,1933, to which reference is made for an understanding of the generalfeatures of the tool and of the operation of all parts thereof notspecifically described herein.

Among the objects of the present invention is to provide a motor-drivenshear which is exceedingly rugged, yet simple in design and constructionand which is efliciently operative to quickly and accurately cut sheetmetal stock along straight lines as well as along curved lines of verysmall radii or of irregular configuration.

An important object of the invention is to provide the shear with anovel construction or" demountable anvil which is adapted to be readilysecured to and removed from the operating head of the tool and whichserves not only as the support for the lower fixed cutting blade of theshear but also as the guide for the upper vertically reciprocablecutting blade which coacts with the fixed blade to shear the stock fedthrough the tool.

Still another and important general object of the invention is toprovide the shear with a work-supporting and guiding plate, otherwiseknown as an anvil, of such design and construction as to facilitatecutting the stock along curves of exceedingly small radii regardless ofwhether the curved lines of cut extend clockwise away from the verticalaxis of the coacting cutting blades or counter-clockwise about saidaxis.

A further object of the present invention is to provide an anvil whichis of such design and construction and which is so fitted with a lower astationary cutting blade in the anvil to more securely lock it in placeand so prevent unintentional oraccidental displacement thereofrelatively to its coacting reciprocating blade; to lessen the strain towhich the unsupported end of the anvil is subjected during operation ofthe 2 tool; to facilitate adjustment of the lower cutting blade as itbecomes worn in use; and to generally strengthen and reinforce theunsupported end of the anvil upon which the stationary cutting blade ismounted.

Other objects and advantages of the present invention will appear morefully hereinafter, it being understood that the present inventionconsists in the combination, construction, location and relativearrangement of parts, all as will be more fully described hereinafter,as is shown in the accompanying drawings and will be pointed out in theappended claims.

In the said accompanying drawings:

Figure 1 is a side elevational view of a shear constructed in accordancewith and embodying the principles of the invention;

Figure 2 is a front elevational view of the shear with the operatinghead thereof shown partly in section;

Figure 3 is a transverse sectional view as taken along the line 3-3 ofFigure 1;

Figure 4 is a transverse sectional view as taken along the line -44 ofFigure 1;

Figure 5 is a vertical sectional view as taken along the line 55 ofFigure 2;

Figure 6 is a bottom plan view of the operating head of the tool asviewed from the line 6-6 of Figure 1; and

Figure 7 is an elevational view showing the demountable anvil separatedfrom the operating head of the tool.

Referring now more particularly to the drawings, it will be observedthat the shear of the present invention is of a form and constructionadapted to be held conveniently in the hand of the operator, theoperating head of the tool, designated generally by the referencenumeral H], being secured in any suitable manner to the forward end ofthe casing II in which is housed an electric motor l2 for driving a mainshaft 13 through the intervention of a gear train designated generallyby the numeral M. The main drive shaft I3 is provided at its end with aneccentric l5 which operates upon an eccentric crank I 6 to effectvertical reciprocation of a cutter bar I! which is generally of circularcross section and extends downwardly through a tubular guide and bearingsleeve l8 provided at the forward end of the casing l I. Theconstruction of the casing H and the design and disposition of the motor[2 and the gear train l4 therein may be varied as desired, it beingmerely noted in this connection that the casing I! is preferablyprovided with a hand-hold l9 which is fitted with a finger-actuatedelectric switch for controlling the operation of the motor. The tubularguide and bearing sleeve 18 may be formed as an integral dependingextension of the gear box portion 2! of the casing II or it may besecured thereto as a separate removable part.

As most clearly appears in Figures 4, 5, and 6, the lower end of thecutter bar IT is notched out at one side thereof, as at 22, to provide avertically extending channeled seat for a cutting blade 23 having abeveled shearing edge 24 which projects below the open end of thechanneled seat 22. This cutting blade 23 is provided in its outersurface with a vertically elongated recess the bottom of which isslotted, as at 25, in registry with a tapped hole 26 formed in thecutter bar IT. A screw 21 disposed with its enlarged head in the recessof the cutting blade and with its shank projecting through the slot 25and into the tapped hole 26 serves to secure the cutting blade 23 invertically adjusted position within its channeled seat 22. In order tofurther secure the cutting blade 23 in position against longitudinalshifting under the impact of each shearing stroke, the upper end of theblade is backed up by a headed screw 28 the shank of which is threadedinto the cutter bar H in vertical alinement with the blade 23. It willbe apparent by that simple rotation of the screw 28 in one direction orthe other, its head 29 may be shifted lengthwise of the channeled seat22 to provide a suitably located upper abutment for the cutting blade23, the screw 2'! being then employed to securely lock the blade in itsseat with the upper end of the blade in abutment with the head of thebacking screw 28. In order to facilitate adjustment of the latter, itshead 29 is provided with circumferentially spaced holes 30 for receptionof a suitable pin (not shown) employed to rotate the screw as desired.

Adapted for detachable securement to the lower end of the dependingtubular guide and bearing sleeve I8 is a combination unit 3! whichserves not only as an anvil, or bed-plate for supporting and guiding thework through the shearing head of the tool, but also as a guide forinsuring rectilinear reciprocation of the cutter bar I! with itsassociated cutting blade 23 and as a support for the lower stationarycutting blade 32 with which the reciprocating blade 23 coacts in theshearing operation. 7

It will be noted that the combination unit BI is provided with a centralportion in the form of an anvil 3P of generally arcuate shape in topplan, the upper flat surface of this anvil spiralling downward from oneend toward the other thereof and the thickness of the anvil 3P beingreduced from its outer peripheral edge 33 inwardly toward its inner edge34. The latter edge follows a curvature of extremely small radius toprovide an opening 35 which laterally communicates with an open-endednotch 36 extending lengthwise of the shearing head in the immediateregion of the reciprocating cutting blade 23.

Extending upwardly from the elevated end of the spiral anvil 31 is atubular post 31 which is provided at its upper end with a radiallyextending flange 38 adapted to be bolted to a complementally formedflange 39 provided at the lower end of the depending guide and bearingsleeve IS. The tubular post 3'! is of the same diameter as that of thesleeve [8 and constitutes a downward extension of the latter when theregistering flanges 38 and 39 are bolted as by,

the bolts 39. It will be noted that the tubular post 3! is verticallynotched along one side thereof, as at 40, to provide a verticallyextending guideway for the reciprocating cutting blade 23, the oppositeside edges of which latter respec-- tively engage the corresponding sideedges of the guide notch 40 to prevent twisting of the cutting bladeangularly with respect to its vertical axis of reciprocation. Thus, thepost 3'! of the anvil member unit 3| serves ,not only to mount thelatter operatively in position with respect to the reciprocatingshearing blade 23, but also to guide the latter for reciprocation alonga definite rectilinear line of travel and in a fixed vertical planeoffset to the right of the vertical axis of the cutter bar when the toolis viewed as in Figure 2.

Extending downwardly from the depressed end of the spiral anvil 3l is avertically extending solid post 4| of generally cylindrical shape, theinner side of this post being milled out, as at 42, to provide avertically elongated seat for the stationary cutting blade 32 alreadyreferred to above. The latter blade is similar in construction to thatof the upper blade 23 in that it is provided with a beveled shearingedge 43 and with an elongated recess 44 in the body thereof, the basewall of the recess being longitudinally slotted, as at 45. The blade 32is secured firmly in its seat 42 by means of a bolt 46 the threadedshank of which projects laterally through the post 4| and the slot 45 ofthe blade for engage ment by a nut 41 seated in the recess 44, It willbe apparent that the blade 32 may be adjusted vertically within its seatto the extent permitted by the length of the slot 45. In order tofurther secure the blade in its adjusted position against verticaldisplacement under the impact of eachshearing stroke, the bottom end ofthe blade is preferably backed up by an axially adjustable screw 48which in turn is locked in place by a laterally extending set screw 49.

It will be noted that when the cutting blades 23 and 32 are respectivelymounted in position and adjusted properly in their seats, the shearingedges thereof are so angularly related as to permit free and easyfeeding of the sheet material to be out between and through said edgesof the blades. Of course, in practice the tool is generally fed into andthrough the material along prescribed lines of cut, during whichoperation the sheared edges of the material are respec: tively deflectedabove and below the anvil 3 so that one portion of the sheared materialrests upon the upper surface of the anvil, while the other portion ridesbeneath the anvil in close contact with its under surface.

In order to provide the operator of the tool with the fullest possibleview of the line of shearing, the flanges 3839 of the vertically alinedsleeve 18 and post 31 are commonly cut away as at 50-50, along atransverse line substan tially coincident with the plane of verticalreciprocation of the upper cutter blade 23. In operating the tool forshearing material along a prescribed line of cut, the tool may be fedstraight through the material for making a straight line out ofindefinite length, or it may be turned to the right or to the left toshear the material along irregular or curved lines. When cutting thematerial along a line curving to the right of the shearing axis, suchline of cut may curve from a straight line of infinite radius to acurved line of a radius as small as that of the upper post 31 of theanvil unit. On the other hand,

when the material is cut along a line curving to the left of theshearing axis, the smallness of the radius of such curvature is limitedonly by the radius of the lower depending post 4! of the anvil unit.Inasmuch as both of the oppositely projecting posts 31 and M are ofsmall external diameter, the material may be sheared in either directionalong lines of exceedingly small radii of curvature and with maximumvisibility to the operator of the line of cut.

Due to the fact that the lowering depending post ll with its associatedcutting blade 32 is of relatively small overall diameter, it becomespossible to insert said post through a small opening formed in the sheetmaterial preliminarily to effecting an inside out in such material. Thisis an important feature of the present tool, because motor-driven shearsprior to the invention have not been constructed to facilitate makinginside cuts except in cases where the sheet material is initiallyprovided with an excessively large opening into which the head of thetool may be inserted.

It will be understood, of course, that the present invention issusceptible of various changes and modifications which may be made fromtime to time without departing from the general principles and realspirit of the invention, and accordingly it is intended to claim thesame broadly, as well as specifically, as indicated by the appendedclaims.

What is claimed as new and useful is:

1. In a hand-held motor-operated shearing tool, a shearing headcomprising a pair of relatively movable cutting blades respectivelyhaving overlapping shearing edges forming an acute angle therebetween, avertically reciprocable bar constituting a mounting for one of saidblades, a tubular guide sleeve for the upper portion of saidreciprocable bar, a tubular extension of said sleeve detachably securedto the latter in embracing relation with respect to the lower portion ofsaid reciprocable bar, said tubular extension being of an overallexternal diameter substantially equal to that of said guide sleeve, aspiral anvil integral with and springing downwardly and laterally fromthe lower end of said extension toward a region spaced to one side ofand below said lower end of said extension, the marginal edge of theupper part of said anvil being tangential with the external surface ofsaid tubular extension, and a solid post depending from the depressedend of said spiral anvil, said solid post being disposed laterally toone side of and below said tubular extension with the vertical axis ofsaid post and extension in parallel relation, said solid postconstituting a mounting for the other one of said cutting blades.

2. In a handheld motor-operated shearing tool, a shearing headcomprising a vertically reciprocable cutter bar having a cutting bladeoperatively mounted upon one face thereof, a tubular guide sleeveembracing the upper portion of said cutter bar and a combinationwork-supporting anvil and stationary cutter blade carrier detachablycarried by said guide sleeve, said combination anvil and blade carrierincluding a part constitutinga tubular extension of said guide sleeveand a laterally extending part in the form of a spiral platen taperingin cross-section from a relatively thick outer edge toward a thin inneredge, and having an upper surface which inclines from one side of theaxis of reciprocation of said cutter bar downwardly, the marginal edgeof said upper surface of the platen being tangential to said tubularextension of the combination anvil and blade carrier, the depressed endof said spiral platen being provided with a stationary cutting bladecarrier in the form of an integral depending post of relatively smalltransverse cross-section disposed in laterally offset relation withrespect to said reciprocable cutter bar and with its vertical axisparalleling that of said bar.

3. In a shearing tool as defined in claim 2 wherein said last-mentioneddepending post is recessed in one vertical face thereof to provide aseat for said stationary cutting blade, and wherein a cutting blade isadjustably positioned in said seat.

4. In a sheairng tool as defined in claim 2 wherein the adjoining endsof said guide sleeve and tubular extension are respectively providedwith mating flanges adapted to be bolted together, said flanges beingcommonly cut away immediately above the shearing zone to provide maximumview of said zone to the operator of the tool.

5. In a shearing tool as defined in claim 2 wherein the tubularextension forming part of said combination anvil and blade carrier isnotched in one side thereof to provide a vertically extending guidewayfor the cutting blade mounted upon said reciprocable cutter bar.

CHARLES E. GRAY.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,759,842 Fossa May 27, 19302,125,556 Gleich Aug. 2, 1938 2,226,241 Gray Dec. 24, 1940 2,244,638Boardman June 3, 1941 2,482,582 Grafe Sept. 20, 1949 FOREIGN PATENTSNumber Country Date 801,154 France May 16, 1936

